The present invention relates to a cathode ray tube socket which is provided with a socket body having a plurality of contacts disposed in a circle and a high voltage discharge gap housing formed on one side of the socket body.
In this kind of cathode ray tube socket a high voltage discharge gap housing is provided on one side of the socket body and the high voltage discharge gap housing comprises a case having housed therein discharge electrodes and a cover for covering the case as disclosed in U.S. Pat. No. 4,649,315 or 4,822,301, for instance. In order to increase the creeping distance between a high voltage electrode and a grounding electrode in the high voltage discharge gap to prevent the generation of an abnormal discharge along the interior surfaces of the case and the cover, there are provided on their inside surfaces ribs 13 and 14 as shown in FIGS. 1, 2 and 3 which are a vertical sectional view of a high voltage discharge gap housing 28 on the opposite side from the socket body, a vertical sectional view taken on the line II-II in FIG. 1 and a horizontal sectional view taken on the line III-III in FIG. 1, respectively. Conventionally, the ribs 14 of the cover 12 are each partially disposed between adjacent ribs 13 of the case 11. Where the spacing of each of the ribs 13 and 14 is small, discharge current does not flow along the wall surfaces of the case 11 and the cover 12 but instead it flows along a line joining the projecting ends of the ribs 13 and 14, skipping over grooves defined by them. For example, when the spacing g between the ribs 13 and 14 is 1 mm or more, the discharge current flows in zigzag along the inner surfaces of the cover 12 and the case 11 as indicated by the line 16 in FIGS. 2 and 3. When the spacing g is less than 1 mm, the discharge current flows straight as indicated by the line 17, and consequently, the creeping distance cannot essentially be maintained large. In other words, the prior art has a defect that miniaturization of the cathode ray tube socket reduces the creeping distance. Further, no measures have been taken against the discharge along the plane of contact between the case 11 and the cover 12.